Denaturant for ethyl alcohol



@et 2, 1934. L. J. FIGG, .JR 1,975,090

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L. J. FIGG, JR

DENATURANT FOR ETHYL ALCOHOL Filed Sept. ll. 1931 2 Sheets-Sheet 2 manfredi ca. a, 19341 tra!) srATEs rA'rrNT ori-ucr;

DENATDRANT FOR IETHYI. ALCOHOL Louis il. llgg, Jr., Kingsport, Tenn., assignor to Eastman Kodak Company, Rochester, N. Y., a corporation ci New York Application September lll, i931, Serial No. 562,26*?

c claims. (ci. 2oz-77) This invention relates to the denaturing of ethyl alcohol, to compositions for use as denaturants and to alcohol so denatured.

It is an object of my invention to provide a 9 denaturant which will render ethyl alcohol containing it uniit for useas beverage, which cannot be economically removed from the alcohol by any known methods, which will not render the alcohol uniit for industrial uses in which coml@ pletely denatured alcohol has customarily been employed, and which Will,be free from methanol.

It is a further object of my invention tor provide a completely denatured alcohol which will be free from methanol. Other objects will hereinafter l appear.

I have discovered that certain oils produced in the purication of the liquid distillate from the destructive distillation of hardwoods may be freed from methanol by washing, and rectied to produce fractions which are very satisfactory denaturants for producing completely denatured alcohol.

The oils which I treat to produce my denaturants may be obtained as indicated in the accompanying ow sheet (Figure 1). Any hardwood materials may be used, but I prefer, for economic reasons, to use a mixture of hardwood forest waste and mill waste from hardwood saw mills. This hardwood is subjected to destructive distillation in oven retorts in known manner, to

produce charcoal and a liquid distillate commonly known as pyroligneous acid. The pyroligneous acid is allowed to settle in settling tanks. At

this point a tarry substance brown as settled 'tar or insoluble tar settles out.

liquid is decanted oi and distilled in a continu- The supernatant l ous rectifying still, which Vseparates it into crude' acetic acid and crude methanol. The .crude methanol is then diluted with sumcient water to 40 produce 30% methanol. Itis at this point that the oils separate out which I purify and fractionate for` use as denaturants, the "oils separating by straticatlon and being decanted oft from the 30% methanol.

It will be understood that I may vary the process by which these oils are obtained, the foregoing being merely illustrative. I may, in fact, obtain them at any suitable step in the purication of crude methanol by whatever method employed therefor.

'I'hese oils obtained in the purification of crude methanol are brownish, pungent liquids with an offensive odor and are insoluble or dilcultly soluble in water.

One method of washing and fractionating these oils is illustrated in the accompanying diagram (Figure 2). The oils are run into a wash tank; water is added to the oils, the mixture is vigorously agitated, and the two layers are allowed to separate. The oil layer separates out on top, while the water layer is drawn oi at the bottom and discarded to the sewer. The washed oil, free `from methanol, is then pumped into the kettle of the rectifying still. This still comprises a bubble-plate column, a dephlegmator and a condenser, and is provided with suitable tanks for receiving the oil fractions. Low-pressure steam is admitted to a heating coil in the kettle to furnish heat for the distillation. 'I'he oils distill over at from 41 to 230 C. The fraction distilling at 70 from 41 to 75 C. is cut to one of the receiving tanks, the 'Z5-150 C. fraction to another, and the 15o-230 C.fraction to a third tank. 'I'he fraction boiling at 'l5-150 C. is that which I prefer as a denaturant, although all three fractions. are useful as such.

The purified oils (the middle fraction) thus obtained have a specific gravity of 0.860-0.880 at 15.6 C. They are soluble to theextent of 84% in a 5% sodium hydroxide solution. They are 80 also soluble in acetone, methanol, methyl acetone, and methyl-ethyl ketone. They are unpalatable and have a very unpleasant odor even when highly diluted, and are soluble in ethyl alcohol in all concentrations necessary for denaturing.

As an ethyl alcohol denaturant, I prefer to use the fraction of these oils which distills at from 75 to 150 C. I may, however, use the fraction which distills at from 41 to 150. C., or I may collect the entire distillate, distilling at from 41 90 to 230 C., in one receiver, and use the whole distillate as a denaturant or I may employ a middle fraction starting at 41 to 100 C. and ending at 150 to 200 C. as will be apparent.

-In denaturing alcohol with my new denaturant, I may add the oil directly to the alcohol. I prefer, however, for convenience in handling and accuracy in measuring, to dissolve the oil first in an organic solvent which is free from methanol and is miscible with ethyl alcohol, such for example, as acetone, and then to add the acetone solution of the oil to ethyl alcohol to produce a completely denatured alcohol. I have found that a mixture of my denaturant oil and acetone con-V stitutes a denaturant for ethyl alcohol which cannot be removed economically by any known method.

Ezrample.-25 cc. of -the fraction of the de natur-ant oil which distills at from 75 to 150 C. is dissolved in 975 cc. of acetone. 50 cc. of this 110 ing range from approximately 75 C. to 150 C..

solution is then added to a liter of ethyl alcohol to make a completely denatured alcohol. If it is not desired to employ the acetone, I may add from 1 to 2 cc. of this denaturing oil directly to one liter of ethyl alcohol. These proportions either `with or without the acetone may be varied considerably as this oil is a powerful denaturant and therefore very economical.

It will be understood that I may vary the proportions of denaturant oil and/or of acetone without departing from the spirit vor scope of this invention; that I may use another organic solvent in place of acetone, so long as it is free from methanol and miscible with both the oil and ethyl alcohol, and that I may even omit the intermediate solvent altogether and add the denaturant oil directly to the alcohol. The omission of al1 methanol from my denaturant or from the denatured ethanol is not, of course, a matter of necessity as the ethanol readily tolerates both. However, one advantage of my denaturant is that it is not poisonous and quite eective without methanol. Hence, ethanol denatured with my denaturant does not require they addition of other substances and has the advantage of being wholly unpalatable yet nonpoisonous and suitable for commercial purposes without danger of being illegally diverted as the denaturant cannot be removed therefrom.

What I claim as my invention and desire to be secured by Letters Patent of the United States is:

1. A methanol-free denaturant for ethyl alcohol which comprises as an essential denaturing element, washed alcohol oil` having a specific gravity of approximately 0.86 to 0.88 and a boilprepared by separating and distilling thefmajor proportion of the oils contained inthe crude aqueous-methanol fraction obtained from pyroligneous crude resulting from hardwood distillation and condensing the fraction boiling between approximately C. and 150 C.

2. A methanol-free denaturant for ethyl alcohol which comprises as an essential denaturing element, washed alcohol oil having a specific gravity o! approximately 0.86 to 0.88 and a boiling range from approximately 75 C. to 150 C. prepared by separating and distilling the major proportion of the oils contained in the crude aqueous-methanol'i'raction obtained from pyroligneous crude resulting from hardwood distillation and condensing the fraction boiling between approximately '75 C. and 150 C., and a solvent for the oil which is miscible with ethyl alcohol.

3. A methanol-free denaturant for ethyl alcohol which comprises as an essential denaturing element, washed alcohol oil having a speciiic gravity of approximately 0.86 to 0.88 and a boiling range from approximately 75 C. to 150 C. prepared by separating and dstilling the major proportion of the oils contained in the crude resulting from hardwood distillation and condensing the fraction boiling between approximately 75 C. and 150 C. and acetone.

.4. Methanol-free denatured ethyl alcohol which comprises 1000 parts ethyl alcohol containing a denaturant comprising as an essential denaturing element, approximately 1-2 parts of washed alcohol oil having a specific gravity of approximately 0.86 to 0.88 and a boiling range from approximately 15 C. to 150 C. prepared by separating and distilling the major proportion of the oils contained in the crude aqueousmethanol fraction obtained from pyroligneous crude resulting lfrom hardwood distillation and condensing the fraction boiling between approximately 75 C. and 150 C.

5. Methanol-free denatured ethyl alcohol which-comprises 1000 parts ethyl alcohol containing a denaturant comprising as an essential denaturing elementhapproximately 1-2 parts of washed alcohol oil having a specic gravity 4of approximately 0.86 to 0.88 and a boiling range from approximately 75C. to 150 C. prepared by separating and distilling the major proportion of the oils contained in the crude aqueousmethanol fraction obtained from pyroligneous crude resulting from hardwood distillation and condensing the traction boiling between approximately 75 C. and 150 C., and approximately 49 parts o! a solvent for the oil which is miscible with ethyl alcohol.

6. Methanol-free denatured ethyl alcohol which comprises 1000 parts ethyl alcohol containing a denaturant comprising as an essential ifs denaturing element, approximately 1-2 parts ofwashed alcohol oil having a-speciiic gravity ofparts acetone. Y

. LOUIS J. FIGG, Jn. 

